Cleaner

Anyone have any suggestions for a good cleaner for the motor? I just recently bought a quad that needs some TLC and the motor is pretty nasty. Almost like the dirt and grime is baked on to the motor. I tried some simple green and some scrubbing but it's not coming off to well.

[zedicus00]

solvent.... diesel works good. white gas, go to a local detailing shop and ask for the strongest degreser they got...

[trick250r]

gunk engine de-greaser its what i use on my chain and sprockets to get the mud/chainwax mixture off after every ride... should work for the baked on dirt